Just need to be GFI protected in unfinished basements, may be 15 or 20 amp. I recommend 20 Amp.

Code requires protection by a GFCI in "unfinished basements". If you have a finished room, it is not needed. In storage areas, shop, utility room, GFCI protection is needed. Unless you are wiring for a specific installation that requires 20 Amp, you do not need 20 AMP wiring or protection. However, 20 AMP isn't a bad idea in a basement since people plug in space heaters and use power tools. Minimal extra cost.